Ordnance-sighting apparatus



BBEZBSe ORDNANCE SlGHTlNG APPARATUS.

APPLICATION FILED NOV. 11| 1918. 1,328,914. Patented Jan. 27, 1920.

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ARTHUR TREVOR DAWSON AND GEORGE THOMAS BUCKHAM, OF WESTMINSTER, LONDON, ENGLAND, ASSIG-NORS TO VICKERS LIMITED, 0F WESTMINSTER,

LONDON, ENGLAND.

Specification of Letters Patent.

Patented Jan. 27, 1920.

Application filed November 11, 1918. Serial No. 262,087.

To all whom t may concern:

Be it known that we, Sir ARTHUR TREvoR DAwsoN, knight, and Sir GEORGE THOMAS BUCKHAM, knight, both subjects of the King of Great Britain, residing at Vickers House, Broadway, Westminster, in the county of London, England, have invented certain new and useful Improvements 1n or Relating to Ordnance-Sighting Apparatus, of which the following is a specification.

This invention relates to sighting apparatus for ordnance having an independent line of sight and has for its chief object to provide improved means for correcting the sight line in both the horizontal plane and the vertical plane for the errors due to ranging c. giving tangent elevation to the gun) when the aXis of the gun trunnions is inclined to the horizontal.

According to the present invention the improved sighting apparatus comprises a plate or other member moving with the gun during elevation, a second plate or other member connected to the first plate so as to be capable of being adjusted about an aXis parallel to the aXis of the gun and adapted to support the sight carrier, and transverse guides and blocks or rollers cooperating between the sight carrier and a part moving with the gun during pointing only, thereby correcting the sight line in the vertical plane as the correction in the horizontal plane is being effected bythe act of adjusting the second mentioned plate.

In order that the said invention may be more clearly understood and readily carried into effect, we will describe the same more fully with reference to the accompanying drawings, in which Figures 1 and 2 are respectively a side elevation and a rear elevation showing one form of the improved sighting apparatus.

Figs. 3 and 4 are sections taken approximately on the lines 3-3 and 4--4 respectively of Fig. 1.

A is an arm (herein termed the sight arm) which is mounted on or forms part of the pointing arm of the carriage and carries a plate B which is angularly displaced about an aXis parallel to that of the gun trunnions through the same angle as the gun during elevation, by means of a parallel motion link Z) whose lower end is pivotally connected to an arm B0 attached to one of the gun trunnions and whose upper end is pivotally connected to an arm bo on a disk Z100 keyed to the plate B. Mounted on the plate B parallel to the longitudinal aXis of the gun, is a cross-leveling axis pin C on which is mounted a second plate D which is capable of being set into the vertical plane by means of a cross-level screw E actuated by a hand wheel E and interposed between the two plates; the said second plate carries the sight carrier D which is prevented from moving with the gun during elevation for range by suitable means on the sight arm A, these means comprising the pivoted blocks or rollers and the guides hereinafter referred to. As the cross-leveling aXis pin C 'is always maintained parallel to the axis of the gun whatever its angle of elevation may be or whatever the inclination of the gun trunnions may be and as the plate D that carries the sight and is mounted upon this pin is kept vertical by adjustment of the cross-level screw E, a horizontal line across the surface of this plate is parallel to a vertical plane containing the gun aXis. Thus the sight line is maintained in a vertical plane parallel to a vertical plane passing through the gun axis in any position of the gun, and the required correction to the sight line in the horizontal plane is thereby obtained. This has the effect of deflecting the sight line relative to its zero position.

To give the correction to the sight line in the vertical plane, the sight carrier D is provided with a transverse horizontalv guide al engaging with a pivoted block or roller a on the sight arm A and is also provided with a pivoted block or roller cl2 engaging with a transverse guide a2 formed on the sight arm at right angles thereto- The effect of these rollers and guides is to tip the sight slightly forward as the deflection described above is put on; this means that a small additional elevation has to be given tothe gun by the pointing` gear, thus correcting for the difference between the actual angle made by the gun axis, in the vertical plane, and the angle recorded upon the dial of the ranging gear.

While the above description shows how the deflection correction due to inclination of the gun trunnions is effected it is to be understood that the aforesaid second plate D can be set to correct for drift of the projectile due to the riling. In this case the said second plate is set by the cross-level screw E so that it lies at a suitable fixed angle to the vertical to give the drift correction required. Ihat We claim and desire to secure by Letters Patent of the United States is :w

l. In sighting apparatus for ordnance having an independent line of sight, the combination with a member moving with the gun during elevation, of a. second member connected to the first member so as to be capable of being adjusted, when the axis of the gun trunnions is inclined to the horizontal, into a predetermined plane about an axis parallel to the axis of the gun, a sight carrier supported by said second member, a part moving With the gun during pointing only, and transverse guides and coperating members between the sight carrier and said part, for varying the angular' position of the sight line in the vertical plane during` the adjustment of said second member. 2. In sighting apparatus for ordnance having an independent line of sight, the combination with a plate moving with the gun during elevation, of a second pla-te connected to the lst plate so as to be capable of being adjusted, when the axis of the gun trunnions is inclined to the horizontal, into 30 a predetermined plane about an aXis parallel to the axis of the gun, a sight carrier supported by said second plate, a part moving with the gun during pointing only and transverse guides and coperating members between the sight carrier and said part for varying the angular position of the sight line in the verticalv plane during the adjustment of said second plate.

3. In sighting` apparatus fokr ordnance having an independent line of sight, the combination With a plate moving with the gun during elevation, of a second plate connected to the first plate so that it can be adjusted into a predetermined plane about an axis parallel to the axis of the gun when the axis of the gun trunnions is inclined to the horizontal, a sight carrier supported by said second plate, a sight arm moving With the gun during pointing only, a. member on said sight arm engaging with a transverse horizontal guide on the sight carrier and a member on the sight carrier engaging with a transverse guide on the sight arm, said guides and members serving to vary the angular position of the sight line in the vertical plane during the adjustment of said second plate.

ARTHUR TREYOR DAWSON. GEORGE THOMAS-BUCKHAM. 

